Specific to the term coined in " internal combustion engine valve train technology ", for automotive, marine, motorcycle and truck engines, where it is being referenced to in this definition, and as set forth originally in the explicative surrounding the Miller mid-lift Patent, # 4, 365, 785 issued to " Jim Miller " in December 1982, regarding rocker arm geometry : over-arcing ( adjective and verb ) relates to the radial path which either end of a rocker arm makes as it follows the inherent arc created from a pre-specified distance of measurement from its pivotal axis ( the radius ), whereby a connection and / or contact is made with respective components : push-rod and valve, both of which operating under linear ( in-line ) definitions of motion.
